α′-HYDROXY-α,β-UNSATURATED TOSYLHYDRAZONES: PREPARATION AND USE AS INTERMEDIATES FOR CARBONYL AND ENONE TRANSPOSITIONS

ABSTRACT

Regiospecifically generated α,β-unsaturated tosylhydrazones dianions are treated with molecular oxygen, yielding α′-hydroxy-α,β-unsaturated tosylhydrazones, versatile intermediates for organic synthesis. They proved to be useful for 1,2-carbonyl and 1,2-enone transpositions, and also permitted the preparation of α′-hydroxy enones in very high yields.

Keywords:

• Carbonyl transposition
• Tosylhydrazones
• Enone transposition

ACKNOWLEDGMENTS

A.M.A. is grateful to CAPES for a fellowship. We thank Dr. P.M. Imamura for fruitful discussions and Ilza M.O. Souza for her constant technical support.